Kathir ibn Abdullah reported: The Prophet, peace and blessings be upon him, said to Bilal, “Learn.” Bilal said, “What should I learn, O Messenger of Allah?” The Prophet said, “Learn, O Bilal!” Bilal said, “I am ready to learn, O Messenger of Allah.” The Prophet said, “Verily, whoever revives a tradition (sunnah) from among my traditions which has died after me, then he will have a reward similar to whoever acts upon it without taking anything away from their rewards. Whoever introduces an innovation with which Allah and His Messenger are not pleased, then he will have a sin similar to whoever acts upon it without taking anything away from the sins of the people.”